Due to the recent explosion in hacking incidents, we were interested at looking into how biological systems can be used to overcome the limitations of current passwords. Although there was the possibility to use DNA as a password, the speed of current sequencing technologies and lack of options for creating randomness without mutating the bacteria to a point where it could not survive were limiting to the success of this option. For that reason we turned to using physical properties of bacteria such as its metabolome in order to create a biological password.

The idea

The first biological password that changes over time! We are looking into transforming bacteria with a unique array of existing iGEM systems to produce a unique signal of secondary metabolites, initially using fluorescence as a proof of concept. Eventually, we will use the system to produce a unique and random configuration of secondary metabolites, as our "key". In order to produce this randomness, alteration of the activity or presence of promoters associated with these metabolites will be applied using one of a few methods currently being considered by the team.
This key will be used to open locked mechanism such as safes and secure doors. We see a system where the measurement of key engineered metabolites such as volatiles will give a distinct mass spectrum. A juxtaposition of a detection technique such as gas chromotography-mass spectrometry and data comparison software will compare the secondary metabolites of the "key" bacteria to the "reference/lock" from which it was taken. If the spectra of both colonies exceeds a threshold of similarity the locked object will become unlocked.
For the key to be practical it would need to be portable, this is where the design of our key transport device comes in. We are currently looking into a system of a similar design to a chemostat where a continual supply of medium will allow maintenance of a culture. Other options we are looking into include the use of freeze-dried cells or microfluidics.
After a certain amount of time, our Key will have to be renewed from the Lock colony, and when this occurs the configuration of the key is shuffled once again to ensure the key and lock are changing.

Project Overview

FOR CHRIS: https://www.youtube.com/watch?v=otCpCn0l4Wo

Creation of different metabolite levels

We are looking at using either of the following methods:

1. Transposon shuffling of promoters between products.

2. Using dCas9 and a randomly selected gRNA from a library of gRNAs that can interfere differentially with the promoters associated with products.

Transposon selection

Tn7 Transposon used due to specific target site selection for its transposition, which is impossible in other transposon species, without this modular increases in promoter activity could not be achieved as random insertions would create a gradient rather than step wise expression pattern of proteins.

Promoter selection

Promoters are selected to have a greatly varied production of products. These will then allow easy recognition of each level 0-3

Bacterial Key Transport

There is a need for a transport mechanism for the key. This presents problems depending on the bacteria used.

In Ecoli Our key transport system would need to:

Keep our colonies alive for a few days.
Potentially could freeze. Freezing is one of the best ways to store bacteria.
The lower the temperature the longer the culture will retain viable cells.
PROBLEM: Ice can damage cells due to localised accumulation of salt, it can also rupture membranes.
SOLUTION: Use glycerol as a cryoprotectant

Team:UNOTT/Description

UNOTT

Description

The idea

Project Overview

Creation of different metabolite levels

Transposon selection

Promoter selection

Bacterial Key Transport

Sponsors

Possible Metabolites

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